Abstract

In many jurisdictions, filtered containment venting systems are an integral part of severe accident management guidelines but are normally only used as a last resort, to be manually activated when the containment pressure approaches the containment failure limit. This approach fails to utilize the capability of the filtered venting system to better control containment pressure throughout an accident and to create capacity for possible future pressurization based on the accident progression. In this paper, smart venting strategies are explored, using a generic single-unit Canada Deuterium Uranium (CANDU) (660 MWel) plant model in MAAP-CANDU, as a means to mitigate the consequences of a severe accident. These strategies are able to account for both current conditions as well as possible future pressurization. The use of strategic venting offers an improvement in maintaining containment integrity, as well as reducing I-131 releases to the environment by about 10% to 31% compared to last-resort venting while being feasible for manual operator actions. Overall, this comprehensive analysis demonstrates the capability of a smart venting strategy paired with a filtered containment venting system as an active mitigation tool.

References

1.
Jacquemain
,
D.
, July
2014
, “
Status Report on Filtered Containment Venting
,” OECD Nuclear Energy Agency Report NEA/CSNI/R(2014)7, accessed Aug. 23, 2022, https://www.oecd-nea.org/nsd/docs/2014/csni-r2014-7.pdf
2.
2015
, “
Severe Accident Mitigation Through Improvements in Filtered Containment Vent Systems and Containment Cooling Strategies for Water Cooled Reactors
,” Proceedings of a Technical Meeting,
International Atomic Energy Agency
, Chapter 1 – Introduction, Vienna, Austria, Report No.
IAEA-TECDOC-1812
.https://legacy-assets.eenews.net/open_files/assets/2012/11/02/document_gw_02.pdf
3.
Bal
,
M.
,
Jose
,
R. C.
, and
Meikap
,
B. C.
,
2019
, “
Control of Accidental Discharge of Radioactive Materials by Filtered Containment Venting System: A Review
,”
Nucl. Eng. Technol.
,
51
(
4
), pp.
931
942
.10.1016/j.net.2019.01.008
4.
Yang
,
J.
,
Lee
,
D. Y.
,
Miwa
,
S.
, and
Chen
,
S. W.
,
2018
, “
Overview of Filtered Containment Venting System in Nuclear Power Plants in Asia
,”
Ann. Nucl. Energy
,
119
, pp.
87
97
.10.1016/j.anucene.2018.03.047
5.
Song
,
Y. M.
,
Jeong
,
H. S.
,
Park
,
S. Y.
,
Kim
,
D. H.
, and
Song
,
J. H.
,
2013
, “
Overview of Containment Filtered Vent Under Severe Accident Conditions at Wolsong NPP Unit 1
,”
Nucl. Eng. Technol.
,
45
(
5
), pp.
597
604
.10.5516/NET.03.2013.712
6.
Canadian Nuclear Safety Commission
,
2015
, “
Study of Consequences of a Hypothetical Severe Nuclear Accident and Effectiveness of Mitigation Measures
,” CNSC, Ottawa, ON, Canada, Report No. CC172-119/2015E-PDF.
7.
Lebel
,
L. S.
,
Morreale
,
A. C.
,
Korolevych
,
V.
,
Brown
,
M. J.
, and
Gyepi-Garbrah
,
S.
,
2017
, “
Severe Accident Consequence Mitigation by Filtered Containment Venting at Canadian Nuclear Power Plants
,”
Ann. Nucl. Energy
,
102
, pp.
297
308
.10.1016/j.anucene.2016.08.005
8.
Morreale
,
A. C.
,
Lebel
,
L. S.
, and
Brown
,
M. J.
,
2017
, “
Effects of Filtered Containment Venting on Fission Product Releases During CANDU Reactor Severe Accidents
,”
ASME J. Nucl. Eng. Radiat. Sci.
,
3
(
2
), p.
020907
.10.1115/1.4035434
9.
Canadian Nuclear Safety Commission
,
2014
, “
REGDOC-2.10.1: Nuclear Emergency Preparedness and Response
,”
Canadian Nuclear Safety Commission
,
Ottawa, ON, Canada
, accessed Aug. 23, 2022, http://nuclearsafety.gc.ca/eng/acts-and-regulations/regulatory-documents/published/html/regdoc2-10-1/index.cfm
10.
Zheng
,
X.
,
Ishikawa
,
J.
,
Sugiyama
,
T.
, and
Maruyama
,
Y.
,
2017
, “
Bayesian Optimization Analysis of a Containment-Venting Operation in a Boiling Water Reactor Severe Accident
,”
Nucl. Eng. Technol.
,
49
(
2
), pp.
434
441
.10.1016/j.net.2016.12.011
11.
Wachowiak
,
R.
, and
Canavan
,
K.
,
2012
, “
Investigation of Strategies for Mitigating Radiological Releases in Severe Accidents: BWR Mark I and Mark II Studies
,” Electric Power Research Institute, Palo Alto, CA, Report No.
1026539
.http://www.eenews.net/assets/2012/11/02/document_gw_02.pdf
12.
Morreale
,
A. C.
,
Shah
,
M. D.
, and
Lebel
,
L. S.
,
2022
, “
Application of Strategy for Filtered Venting and Effects on CANDU Severe Accident Source Terms
,”
19th International Topical Meeting on Nuclear Reactor Thermalhydraulics (NURETH-19)
, Brussels, Belgium, Mar. 6–11, p.
17
, Paper No. 35034.
13.
Mathew
,
P. M.
,
Petoukhov
,
S. M.
, and
Brown
,
M. J.
,
2007
, “
An Overview of MAAP4-CANDU Code
,”
Proceedings of the 28th Annual Conference of the Canadian Nuclear Society
, Saint John, New Brunswick, Canada, June 3–6, Theme 2 – Safety Analysis, p.
13
.
14.
Saliba
,
N.
,
Komljenovic
,
D.
,
Chouinard
,
L.
,
Vaillancourt
,
R.
,
Chrétien
,
G.
, and
Gocevski
,
V.
,
2010
, “
A Proposed Structural, Risk-Informed Approach to the Periodicity of CANDU 6 Nuclear Containment Integrated Leak Rate Testing
,”
31st Annual Conference of the Canadian Nuclear Society
, Montréal, QC, Canada, May 24–27.10.13140/2.1.1730.4327
15.
Eckardt
,
B.
, and
Losch
,
N.
,
2012
, “
Filtered Containment Venting System Designs
,” US NRC Meeting on Containment Venting Systems, July 12, Rockville, MD, accessed Aug. 23, 2022, https://www.nrc.gov/docs/ML1220/ML12206A263.pdf
16.
Petoukhov
,
S. M.
,
Brown
,
M. J.
, and
Matthew
,
P. M.
,
2009
, “
MAAP4-CANDU Application to the PSA Level 2 for the Point Lepreau Nuclear Generating Station Refurbishment Project
,”
Proceedings of the Canadian Nuclear Society 30th Annual Conference
, Calgary, AB, Canada, May 31–June 3, pp.
1052
1064
.
17.
Canadian Nuclear Safety Commission
,
2014
, “
Design of Reactor Facilities: Nuclear Power Plants
,” Physical Design, REGDOC-2.5.2.
18.
Canadian Standards Association
,
2016
, “
Requirements for Beyond Design Basis Accidents
,” N290.16-16.
19.
Canadian Standards Association
,
2016
, “
General Requirements for Nuclear Emergency Management Programs
,” N1600-16.
20.
Bentaib
,
A.
,
Meynet
,
N.
, and
Bleyer
,
A.
,
2015
, “
Overview on Hydrogen Risk Research and Development: Methodology and Open Issues
,”
Nucl. Eng. Technol.
,
47
(
1
), pp.
26
32
.10.1016/j.net.2014.12.001
You do not currently have access to this content.